The effects of air exposure and occlusion on the mitotic response to wounding were studied. Sites on the dorsal skin of six human volunteers were tape-stripped to remove the stratum corneum. This series of wounds was left either air-exposed, or covered by an occlusive film.

The magnitude and duration of mitotic response were significantly greater in the air-exposed than occluded wounds. The wounded epidermis returned to the baseline levels of cell division at seven to ten days with occlusion and at 12 to 14 days with air exposure.

The mitotic response to tape-stripping is mediated in a two fold manner: (1) mitosis induced by removal of the stratum corneum, and (2) a second, additive mitotic response to a loss of cells in the malpighian layer.